Commit f796c20c authored by John Fastabend's avatar John Fastabend Committed by David S. Miller

net: netprio: fix files lock and remove useless d_path bits

Add lock to prevent a race with a file closing and also remove
useless and ugly sscanf code. The extra code was never needed
and the case it supposedly protected against is in fact handled
correctly by sock_from_file as pointed out by Al Viro.

CC: Neil Horman <nhorman@tuxdriver.com>
Reported-by: default avatarAl Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: default avatarJohn Fastabend <john.r.fastabend@intel.com>
Acked-by: default avatarNeil Horman <nhorman@tuxdriver.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 16c0b164
...@@ -277,12 +277,6 @@ static int write_priomap(struct cgroup *cgrp, struct cftype *cft, ...@@ -277,12 +277,6 @@ static int write_priomap(struct cgroup *cgrp, struct cftype *cft,
void net_prio_attach(struct cgroup *cgrp, struct cgroup_taskset *tset) void net_prio_attach(struct cgroup *cgrp, struct cgroup_taskset *tset)
{ {
struct task_struct *p; struct task_struct *p;
char *tmp = kzalloc(sizeof(char) * PATH_MAX, GFP_KERNEL);
if (!tmp) {
pr_warn("Unable to attach cgrp due to alloc failure!\n");
return;
}
cgroup_taskset_for_each(p, cgrp, tset) { cgroup_taskset_for_each(p, cgrp, tset) {
unsigned int fd; unsigned int fd;
...@@ -296,32 +290,24 @@ void net_prio_attach(struct cgroup *cgrp, struct cgroup_taskset *tset) ...@@ -296,32 +290,24 @@ void net_prio_attach(struct cgroup *cgrp, struct cgroup_taskset *tset)
continue; continue;
} }
rcu_read_lock(); spin_lock(&files->file_lock);
fdt = files_fdtable(files); fdt = files_fdtable(files);
for (fd = 0; fd < fdt->max_fds; fd++) { for (fd = 0; fd < fdt->max_fds; fd++) {
char *path;
struct file *file; struct file *file;
struct socket *sock; struct socket *sock;
unsigned long s; int err;
int rv, err = 0;
file = fcheck_files(files, fd); file = fcheck_files(files, fd);
if (!file) if (!file)
continue; continue;
path = d_path(&file->f_path, tmp, PAGE_SIZE);
rv = sscanf(path, "socket:[%lu]", &s);
if (rv <= 0)
continue;
sock = sock_from_file(file, &err); sock = sock_from_file(file, &err);
if (!err) if (sock)
sock_update_netprioidx(sock->sk, p); sock_update_netprioidx(sock->sk, p);
} }
rcu_read_unlock(); spin_unlock(&files->file_lock);
task_unlock(p); task_unlock(p);
} }
kfree(tmp);
} }
static struct cftype ss_files[] = { static struct cftype ss_files[] = {
......
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